Let's see...
When I was trying to find the Deoxys I wanted, I got one off the GTS for one of my extra shinies, so that was a pretty good deal for me. Then I just kept switching the Deoxys I would get for another if it wasn't the nature I wanted.
When I finally got the timid Deoxys I was looking for, and once I had gone through the tedious task of getting rid of all its EVs (it was at level 76 or so when I got it), I was pleased to find that it not only had a good nature, but most of its IVs were in or around the 20s range. =] I was quite happy. Definitely my best GTS grab, and currently my best pokemon, too.
Oh, and my little sister scored recently too-- she found a shiny Gastly that was up for trade in return for a Flaffy. I thought she wouldn't be able to make it, what with having to transfer the thing from her old games, but she did.